As an example of the opto-reflector in the related art, a configuration example of a surface mount type opto-reflector having a light emitting element and a light receiving element mounted on a substrate is illustrated. FIGS. 8(A) and 8(B) are views illustrating a configuration example of an opto-reflector in the related art, wherein FIG. 8(A) is a plan view seen from the top of the element and FIG. 8(B) is a side sectional view seen from the side.
In the opto-reflector 100 of the related art, a light emitting element 103 and a light receiving element 104 are mounted on a substrate 101, and the light emitting element 103 and the light receiving element 104 are sealed with a light transmitting resin layer 102. Between the light emitting element 103 and the light receiving element 104, a light shielding wall 107 made of a resin having a low beam transmittance is provided in order to reduce noise due to the direct beam being transferred between the elements. As an example of providing a light shielding wall between the light emitting element and the light receiving element, there is a proximity sensor disclosed in, for example, Patent Literature 1.